


Rabbit Heat

by RubyMagnolia



Category: Voltron: Legendary Defender
Genre: Body Expansion, Chubby Shiro, Expansion Suit, M/M, Safe Sane and Consensual, Sex Magic, Transformation, Weight Gain, bunny - Freeform
Language: English
Status: Completed
Published: 2017-09-13
Updated: 2017-09-13
Packaged: 2018-12-27 07:58:08
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,111
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/12076869
Author URL: https://archiveofourown.org/users/RubyMagnolia/pseuds/RubyMagnolia
Summary: Shiro buys a bunny costume, fully knowing what will happen. Lance is surprised but into it.Magical, rapid weight gain and expansion. Don't like? Don't read.





	Rabbit Heat

It had all started with a bunny costume.

Naturally, it had been Lance's idea to dress up. It had been Shiro's choice of costume, and there had been a wide variety of them to choose from in the small sex shop they had found in one of the space malls Voltron visited for supplies.

"How about a devil?" said Lance.

"Mm, no," said Shiro firmly.

"Nurse?"

"No."

"Doctor?"

"Rather be a nurse."

"Cowboy."

"I don't think so. Also how the quiznak do they know what a cowboy is?"

Lance pulled out the wrapped costume and looked at the preview image printed on the front.

"Uh, it doesn't specifically say cowboy, it just looks like it," said Lance.

Shiro nudged at Lance to move over, and he started flicking through the racks of costumes. They had special effects, promised the packaging, and each type, cut, or even colour could affect the experience. The thing was, they could only read bits of it – Shiro more than Lance – and the translator Pidge had programmed for the team struggles with euphemisms and colloquialisms.

"'Fur leg fast hot.' Shiro, what does this say?" asked Lance.

He held out another packet, one that looked suspiciously like a Playboy Bunny suit from back on earth, except the alien on the front looked much bigger than any Playboy Bunny. Shiro read the label, paused, read it again, and blushed.

"It says 'fuck like a rabbit.' The Galra equivalent of a rabbit and fucking like one," said Shiro. "I like this one."

What he didn't mention was that Lance would get an extra surprise.

•

It took a while before they had the chance to have a night to themselves. Shiro was looking forward to it. If the suit did as it promised, he'd finally be able to keep up with Lance. The whole reason for looking at sex supplies in the first place was that Shiro had never really had an easy time with sex.

The costume promised that it was infused with skin-absorbed aphrodisiacs that would hopefully help them have a good night. Maybe Shiro would actually orgasm this time. Lance had suggested going to an alien sex shop because he felt bad that Shiro very rarely orgasmed, and even more rarely took any enthusiasm from it. Even though Shiro always seemed to enjoy himself, it never seemed like it was as mind-blowing for him as Lance felt. So tonight was about making sure Shiro feel good about himself.

As Lance made himself comfortable on Shiro's bed, setting up a bottle of lube and a range of condoms, Shiro slipped into the tiny private bathroom that adjoined his room.

He pulled the main suit on first, wriggling a little before yanking at the front to cover his chest. There was a moment where he thought he had misread the packet and it was actually meant for a larger person than him, before it sealed to his body. It was a peachy colour, shimmering lighter or darker depending on the light and stretch. He then put the ears and stay-up stockings on, adjusting the rabbit headband in the mirror so it was perfectly straight. The ears matched his hair, pitch black with white tips, same as the tail that was snap-buttoned to the suit, hiding a hole.

There was a slight shine to the bunny leotard, like latex, but not nearly as tight. Shiro ran his hands over the suit, fingers running under hems to make sure they were even. He glanced over his shoulder to look at the fluffy black and white tail, wriggling his hips to watch it twitch.

Shiro turned back to the front, making one last check of everything, and took a deep breath to leave his bathroom. Lance was waiting on Shiro's bed, jacket discarded, and he whistled as Shiro came out.

"You look great," said Lance.

"I feel cute," said Shiro.

He glanced down to where his cock was bulging. Damn, he looked huge and he wasn't even hard yet. Had to be the way the suit was cupping him.

"Obscenely cute," he joked.

"Come here, I wanna touch you," said Lance.

Shiro obliged, Lance standing up to meet him half way. Putting his hands on Shiro's hips, Lance encouraged Shiro to spin for him.

"I'm glad you went for this one," said Lance. "Oh, your tail matches!"

Cooing, Lance spun Shiro back around and hugged him, pulling their hips together in an easy grind. Shiro shivered, feeling a little tingly but not what one would call "in heat." Still, it felt nice, and he pushed back, rolling his hips upwards.

 

 

Lance's hands started to wander downwards. Even without having to ask, Shiro knew where they were going: straight for his ass. Even though Shiro didn't think there was much of it to be had, Lance loved it, and liked to touch it at any opportunity. This time it felt sensitive, and Shiro let out a tiny gasp. He felt his face go red in his cheeks. Chuckling, Lance squeezed gently, drawing out another noise from Shiro.

"Feel anything?" asked Lance.

"Starting to," said Shiro. "Is this how you always feel when you have sex with me?"

"Pretty much. You're _hot_ and you have no idea how hard it is not to pop a boner whenever I see you," said Lance.

Even now, Lance had to remind himself that the growing stiffness in his jeans had to be told to calm the fuck down. He wanted to get Shiro off first. Hopefully more than once.

Then Shiro let out a whimper. He pushed forward, trying to get his hips flush with Lance's. Letting go of Shiro's ass, Lance brought both hands around to cup Shiro's crotch, palming the bulge of his length with one, and rubbing at the balls underneath with the other. Shiro shivered, eyes going dark, and his suit showing his perked nipples.

"Harder, please," Shiro said.

The suit had kicked in. This was fun. Even though they had planned for this, it seemed more spontaneous. He felt like this was only the first of many orgasms he was going to have. Shiro barely had time to process these thoughts before Lance pressed more firmly.

Shiro practically screamed, pressing into the touch. He was redder now, flushed across his face and neck, his bare shoulders a dusty rose, and a slight sheen to his skin. Uncertain of where to put his hands, Shiro took a grip on Lance's shoulders, losing his composure as Lance kneaded and rubbed, fingers slipping under the hem of the costume, teasing to release Shiro's cock from its confines but never quite getting there.

It didn't matter, as Shiro came in under a minute, cum coating the inside of his costume. He shuddered, curling around Lance, hips jerking three times before stilling. Lance was impressed: the suit hadn't leaked and it didn't show any visible signs that there was a layer of cum in it.

"Sorry! I'm sorry! I didn't mean to–" Shiro started.

Lance kissed Shiro on the nose, nuzzling into Shiro's neck.

"Did you like it?"

"Yes," replied Shiro. "But you–"

"If you liked it, then good. Don't worry about me," said Lance.

He kissed Shiro again, this time on the lips. Gosh, Shiro was a cute bunny, ears pointing straight up, with such a good fluffy tail. It wasn't real but dang did it look great anyway.

Lance let his hands wander back down to Shiro's rump, grabbing it.

"Huh," said Lance.

It felt like there was more to grab. There was just a little more bounce, a bit more roundness to it.

"God this suit is tight," Shiro murmured.

Then Shiro moaned, hands going to his ass, brushing over Lance's. There was a popping noise, and the false tail fell to the ground. Lance's eyes widened.

"Shiro, you–"

"It's okay," said Shiro. "It was meant to happen. Can you pull it out?"

He spun around to put his back to Lance.

A magnificent puff of a rabbit's tail had sprouted through the hole on Shiro's costume. Lance tugged at it, making sure all of it was out.

"You grew a rabbit's tail," said Lance, shocked.

That wasn't all that had grown. Looking at it now, Lance could pretty confidently say Shiro's tight ass was bigger, the costume stretching to accommodate it.

"Yes. Fuck, that feels good," moaned Shiro, hands slipping between his legs.

Shiro's headband fell to the floor, his human ears stretching upwards, turning soft, with a layer of black fur growing over them. Shiro's tail fluttered in delight, as he spared one hand to touch his new rabbit ears.

He looked at Lance, trying to gauge how his lover felt about these new developments. For once it seemed like Shiro had managed to fluster Lance. Shiro turned to face Lance once more, touching the front of Lance's jeans.

"Not a boner killer, I see," said Shiro.

"Quiznak. No. Shit, this is hot," said Lance.

Lance lunged forward, hands sliding over Shiro's waist, the costume starting to look like Shiro had been sewn into it a size too small. Shiro's ass was visibly turning into a bubble butt, that thick rump complemented by widening hips. It wasn't a surprise to Shiro, however, and he grinned.

He was visibly gaining weight, the sculpted body softening before Lance's eyes. While it had started behind, the gains were shifting forward and down. The stockings Shiro was wearing started to cut in as his thighs doubled in size, fat pinching out from the gap between the suit and stocking. A small belly started to swell, Shiro rubbing it half out of the tingling pleasure it was giving and half from curiosity.

"You're getting fat," exclaimed Lance.

"It's fine. This was meant to happen," said Shiro.

"This was–"

"I feel good," said Shiro. "Here, touch me."

He grabbed Lance by the shoulders and started to rock his hips up against him. A second erection tented in the costume, caught between Shiro's growing gut and Lance's own stomach. The soft, squishy belly pressed between them, Shiro letting out choked moans and shallow breaths.

"You're so chubby," murmured Lance.

Shiro whined, and suddenly pressed Lance's head to his chest. Here, too, Shiro was plumping up, his pecs rounder, nipples growing thicker and bigger. When Lance pulled back, he noticed that Shiro's jawline wasn't as harsh, fat appearing around his neck. By now, it felt like Shiro had doubled in size, his body ballooning in the costume as it stretched to accommodate.

In another few moments, Shiro had outgrown Hunk, and Lance nearly came on the spot as Shiro pushed them back onto the bed. Rolling over, Shiro leaned back on his prosthetic arm, other hand clutching his belly, legs spread as if he were about to give birth.

Judging by the nearly frantic way in which Shiro tried to pull out his cock, he had entered the "heat" that the suit had promised.

"Come on, fuck me," begged Shiro.

The growth had seemingly stopped, and Lance was torn between this version of Shiro and regular Shiro as to who was hotter. He clambered onto the bed, pushing his hand between Shiro's legs. Shuddering, Shiro had his second orgasm of the night.

The suit had one final trick. Squirming around, Shiro arched his back, suit miraculously holding his cock and balls in as they swelled up. Lance was certain that Shiro's balls would have popped out the side of the suit, but there they hung, round and heavy between Shiro's legs.

This was the best night ever, Lance decided.

"Touch me, Lance."

"Hm, I think we can make this better with a bit of denial, Takashi," said Lance.

Shiro shivered as Lance used his real name, hands trying to reach his cock under his belly. It was in vain though, the mass pinning him down more than he expected, his girth too much for him to bypass.

Lance crawled up to Shiro, and kissed him, locking lips as a way of distracting Shiro. It was about time he got off, and he threw one leg over Shiro's. The thick flesh felt good, Lance straddling it in delight.

"Wow," said Lance. "I wasn't expecting this but damn you look and feel so, so good. So thick."

"The view is pretty from where I am," moaned Shiro.

Still in his jeans and shirt, Lance rutted against Shiro. It was Shiro pulling Lance back into his chest again that tipped Lance over the brink. He dismounted, panting, and finally gathered the energy to shimmy his jeans and boxers off.

"Lance," whined Shiro.

"You're so cute when you're in heat!"

Shiro could practically see the hearts pouring out of Lance's words, but he was horny and hard and he wanted to be touched again.

"Please?"

"Okay, okay," said Lance.

He sat up, this time positioning himself between Shiro's spread legs, face close enough that Shiro could feel his breath on his crotch and plucked at the leotard. Lifting the fabric, Lance was nearly smacked in the face with the thick, red cock that sprung free.

"Woah," he muttered. "Easy there."

There was no way that Shiro's cock was going to fit inside Lance without preparation. Besides, Lance wasn't keen on receiving anal anyway.

"Pass me the biggest condom I've got," ordered Lance.

Shiro shifted, barely managing to grab the box of condoms and rifled through it. He tossed a shiny pink one to Lance, who caught it. Rolling it on was a task, since Shiro couldn't stop quivering in anticipation, but Lance managed it.

Then he went down on Shiro, and he was pretty sure the whole Castle would have heard them even with soundproofing.

If there was one thing Lance felt he was good at, it was blowjobs. Sucking, gripping, teasing, he could do it all. The condom tasted like lime, something he was glad of for the tang. The closer Lance drew Shiro to completion, the closer Shiro's thighs pressed down on him, keeping him to task.

When Shiro flopped back after his third orgasm, Lance pulled back with satisfaction, and crawled up to rest his head and arms on Shiro's tummy.

"Still got enough for one more round?" asked Lance.

Panting, Shiro put his hand out to ruffle Lance's hair, his ears flicking forward.

"Is it your dick in my ass?" asked Shiro.

"Absolutely," said Lance.

Shiro grabbed the condom box again, and pulled out one for Lance and another for himself. Lance put Shiro's on first, then his own.

"Lube?" asked Lance.

Shiro passed the bottle, then rolled onto all fours, hands managing to pull the back of the leotard aside to spread his ass. Taking out a disposable rubber glove that was in the same box as the lube, Lance slicked up and inserted one finger, then two to prep Shiro. It didn't take long to add a third and fourth, Shiro having prepped earlier. He removed his fingers, smiling at the needy noise Shiro made, and peeled off the glove.

Carefully, he pushed in, making sure he still had plenty of lube to ease in. Shiro's hands clenched at the sheets, but he stayed still. Roughness wasn't a part of this. Shoving back would spoil it.

"That's great, that's perfect," said Shiro, trailing off into babbled nonsense.

Lance rubbed Shiro's back, tweaked the tail that was in perfect reach, and slid in all the way. Pausing to make sure Shiro was still comfortable, Lance started a rocking motion. Encouraged by the yips of delight underneath him, Lance went a little faster, starting to pull out before thrusting back in.

"Who's my favourite bunny?" asked Lance, and he was surprised that it had come out at all.

"I am," said Shiro.

"You're so good, so good, I love you," said Lance.

He leaned into it now, grabbing the thick lovehandles that had formed on Shiro's hips. Shiro's ass bounced magnificently with their motions, and Lance patted it fondly.

"So nice and juicy," sighed Lance.

"Ye-yes. A bit faster, please, please, please," Shiro said.

"You are so handsome like this, all puffy and fat. You look so happy and content with a nice squishy belly and pecs."

"I am happy. Faster! Oh," gasped Shiro. He shuddered, hips snapping back, "Fuck I'm close."

Lance could feel the heat building, his own release also close. Feeling reckless, he picked up the pace, and Shiro screamed his name, riding out the longest orgasm Lance had ever known. Just before it subsided, the sparks built up and burst in Lance, a dizzying euphoria taking him. When he came down, Shiro was easing himself off Lance's dick and turning around to help with the condom.

"Mine's a bit full," said Shiro, apologetically.

Lance sighed as his condom came off, then bent down to deal with Shiro's. He blushed at the sight, the condom nearly dripping with cum.

"Wow," Lance said.

They got it off and in the bin without spilling anything, and Shiro rolled off the bed to go soak his costume in his sink.

When he came back out, he was nude, and Lance could fully appreciate how chubby Shiro had grown. He wasn't joking when he said he thought Shiro was handsome, especially like this. The belly didn't seem as big as it had while in the thrills of sex, and maybe it had shrunk since Shiro didn't have the costume on anymore, but Lance was desperate to cuddle anyway. Meaty hips and thighs jiggled as Shiro walked.

The bed bounced Lance up when Shiro flopped onto it and started cleaning up with a damp cloth.

"Did you like that?" asked Lance.

"If we weren't so busy, I'd want to do that every night," said Shiro.

He wiped Lance's legs down, and then his own where cum had dried around his crotch.

"How many uses does the costume have?" asked Lance.

"Ten, I think. Well, nine now. You can buy refills," said Shiro.

He snuggled up to Lance.

"I love you," he said.

Lance threw an arm over Shiro's shoulders, and kissed him on the nose.

"I love you too, Takashi."

•

The next morning, Lance was delighted to note that Shiro was still a little chubby even if the tail and rabbit ears had vanished, squeezing into his clothes. Shiro had to suck in his belly to do up his pants, ass filling out the rear nicely, shirt pulling over a small gut, and thighs putting serious strain on his seams. Best of all, Shiro needed help to do up his vest, stuck on not just his gut, but his pecs as well.

"Do I look okay?" asked Shiro.

"You look perfect," said Lance.

**Author's Note:**

> If you enjoyed this, feel free to drop me a line here or [on my tumblr](rubymagnolia.tumblr.com).
> 
> Also, [here's some art that I drew that inspired the fic in the first place.](http://rubymagnolia.tumblr.com/post/165214638110/chubby-shiro-with-lance-for-something-different)


End file.
